Review of methods used to estimate maternal mortality

News article 14 Mar 2017
Measuring MMR in Nigeria

We have recently published a research paper entitled 'Measuring maternal mortality: a systematic review of methods used to obtain estimates of the maternal mortality ratio (MMR) in low- and middle-income countries'.

Reducing maternal mortality is one of the priority goals on the international agenda—the new global target is to reduce the maternal mortality ratio (MMR) to <70 maternal deaths per 100 000 live births and country should reduce their MMR by at least two-thirds from the 2010 baseline and no country should have an MMR higher than 140 deaths per 100 000 live births by 2030.A cross-cutting priority for the post-2015 agenda is to move toward counting every birth, maternal death and perinatal death through the establishment of effective national registration and vital statistics systems in every country, as stated within the recommendations of the Commission for Information and Accountability.

Read the full article on the Oxford Academic website

Reliable data are needed so that adequate resources can be allocated to maternal health programmes for countries (or regions in countries) that are not yet accelerating the annual reduction in maternal deaths. These data are also needed to monitor progress toward the targets set for the new Sustainable Development Goals (SDG). Assessing progress has been a challenge because <40% of countries currently have complete civil registration (CR) systems in place or other methods to provide accurate and contemporaneous MMR data. Similarly, although Maternal Death Surveillance and Review is promoted and being implemented in many settings, attribution and reporting of cause of maternal death is not yet systematically in place. Only 2 of the 49 least developed countries have >50% coverage with regard to death registration.1

The World Health Organization (WHO) publishes global estimates of MMR based on United Nations statistical models, including estimates for countries without reliable data. Most of these estimates are subject to greater or lesser degrees of uncertainty and this is a recognized limitation. There are, in addition to modelling, a variety of methods available to measure MMR including via censuses, household surveys, Reproductive Age Mortality Studies (RAMOS) and using the Sisterhood methods. Each method has strengths and weaknesses. This may include cost of application of method, lack of in-country capacity to use the method and requirement for large sample sizes to be able to estimate MMR with reasonable accuracy. Although some of these methods have been used in a number of developing countries, there is a lack of knowledge and guidance regarding which method(s) are the be most appropriate and feasible to use in which settings (e.g. large or small population, national or sub-national application and type of data required to estimate MMR).

We, therefore, conducted a systematic review of the literature to identify which methods have been used to estimate MMR and reviewed their use and applicability to low- and middle-income countries. The specific research questions included: what are the type of data and data sources required, what are the strengths and weaknesses of each method; and which method(s) would be useful and applicable in low- and middle-income settings and able to provide reasonably accurate and contemporaneous data.